Archive for the ‘Infrastructure’ CategoryOctober 25, 2012
Des Moines Water Works Fleur Drive Treatment Plant has the option of three different sources of raw water. The first and best source is a shallow groundwater collection system called the infiltration gallery. It is a three-mile long, porous pipe constructed with concrete rings. This runs parallel to the Raccoon River in Water Works Park, and collects water from the sands and gravels of the river valley. The ponds in the park are also there to help recharge the gallery. It provided all the water to the Des Moines area until 1949.
Increased water demand required construction of an intake on the Raccoon River in 1949, and the drought of 1977 precipitated construction of an intake on the Des Moines River in 1980.
Des Moines Water Works selects its source of water each day, and sometimes can change throughout the day, due to water quality and the ability to treat different substances present in the source water.
Some of the challenges Des Moines Water Works is faced with in selecting the best source water include:
- Availability: The first choice would be the gallery, but most days there is not enough capacity to supply all the water needed, so a second source is needed to supplement the gallery.
- Algae and bacteria: These can cause treatment challenges, such as plugging filters or taste and odor issues.
- Nutrients: Some of these are naturally-occurring in the environment, but most are man-made. They can be from sources such as agriculture, livestock, or wastewater treatment.
- Other: Turbidity (cloudiness of the water), hardness (dissolved minerals in the water), organic material (plant decomposition) or taste and odor.
- Episodic events: There may be an accidental spill or chemical release into the river.
- Cost: The gallery and Raccoon River are available at the Fleur Drive Treatment Plant, but the Des Moines River has to be pumped five miles from the intake to the plant. This adds additional cost when Des Moines Water Works must use the Des Moines River.
Many of the challenges Des Moines Water Works sees changes daily, so monitoring is done continuously. Evaluating the source water and determining what is the best available and at the cost is to treat that source ensure Des Moines Water Works can deliver water you can trust for life.
There are nearly 10,000 fire hydrants in the Des Moines Water Works distribution system, and while fire hydrants are a familiar sight, the business end of the hydrant is something that many people will never see.
Like an iceberg, there is actually more of a fire hydrant below the ground than there is above the ground. That is because fire hydrants must connect to the water main and the water must be controlled far enough below ground to ensure that water in the piping will not freeze. If water freezes inside a fire hydrant during the winter months, the ice will block the flow of water rendering the hydrant unusable in an emergency situation.
A fire hydrant is basically a pipe with threaded fire hose nozzles at the top (above ground), and a water control valve at the bottom (six feet below ground). Fire fighters use a special wrench to open the hydrant’s water control valve which allows water to flow up the “pipe” (the barrel of the hydrant) and out the nozzles. When the hydrant is shut off, any water left in the barrel drains out through specially designed drain openings which only open when the hydrant is not in use.
Bonus: Do you know why the tops or “bonnets” of fire hydrants are painted different colors? Learn here.
There are more than 10,000 hydrants in the Des Moines Water Works distribution system, and while fire hydrants are a familiar sight, we should all be aware of the importance of each hydrant to the community – not only for firefighting, but also for operation and maintenance of the water system.
Because they are so important, the fire hydrants in Des Moines Water Works distribution system receive a lot of attention. Each public fire hydrant receives regular maintenance on a three-year rotating schedule. In addition, each year in the fall, every fire hydrant is inspected to ensure it is not holding water that could freeze and to confirm that it has not been hit by vehicles or damaged in some other way. Most hydrants in the system are designed to break away if they are hit by a vehicle. This reduces damage to the vehicle and the hydrant and allows the hydrant to be returned to service quickly.
Des Moines Water Works is responsible for maintenance of the fire hydrants that fire fighters use to protect our community. Help the local fire department and Des Moines Water Works by following these simple tips to keep fire hydrants working properly and accessible when they are needed:
- Keep cars, bikes, toys and other objects away from fire hydrants at all times.
- During winter months, shovel snow away from fire hydrants.
- Mow and trim grass or weeds around fire hydrants near your property.
- Do not plant flowers or shrubs around fire hydrants.
- Do not paint fire hydrants – the color of the fire hydrant is indicative of water flow available for fire protection.
Unauthorized use of a hydrant can cause significant damage to the distribution system, the hydrant and your home or business plumbing. Additionally, it may cause damage to our water supply. Any unauthorized use of a fire hydrant may result in a $1,500 fine and misdemeanor charges.
If you notice a damaged fire hydrant or witness suspicious activity near a fire hydrant, please call Des Moines Water Works at (515) 283-8700. Your call is important to the fire protection of your home, business and others around you.
Tip: Do you know why the tops or “bonnets” of fire hydrants are painted different colors? Learn here.
Water main breaks are often associated with cold, icy weather. But when hot, dry weather increases customers’ water demand for irrigation, recreation and hydration, main breaks can be just as frequent.
Des Moines Water Works water pumpage record of 92 million gallons a day (mgd) was set in June 2006. Pumpage has yet to reach that level in 2012, but demand is increasing.
Central Iowa is fortunate to have sufficient sources of water to meet the needs of residential, business, industrial, and governmental customers. In addition, Des Moines Water Works has made significant financial investments in treatment plants, pumps, tanks, piping, and reservoir storage to meet customers’ drinking water needs.
These assets can be affected by increased demand. Water demand puts stress on older water mains throughout the water distribution area which may lead to a break.
If a main break occurs in your neighborhood, Des Moines Water Works crews work quickly to make the repair and restore water service. Due to the urgency of such situations, our crews make the repair process their top priority. Occasionally, this means water service may be interrupted for periods of time without prior notification.
If you see water in the street, please call Des Moines Water Works at.283-8700. Our Water Distribution team can determine the cause and arrange for any necessary repairs. With early detection, a repair can be made more quickly.
As long as Des Moines Water Works has been in existence, protecting the water resources from pollution and assuring an adequate supply of water well into the future has been utmost importance. Thanks to the utility’s founding fathers – not to mention employees throughout the years – the growth of Des Moines Water Works has kept pace with the expanding needs of the community.
In 1884, the company began constructing an infiltration gallery system that would use groundwater from the Raccoon River. The infiltration gallery was the only water source at the time.
By 1919, the water supply grounds covered approximately 470 acres.
In 1925, when the Board of Water Works Trustees purchased 334 acres of land south of the Raccoon River, west of S.W. 30th Street, General Manager Charles Denman stated that the newly acquired land would insure a potential water supply large enough for a city twice the size of Des Moines.
Gradually, additional land (now known as Water Works Park) bordering the Raccoon River on both sides, extending to 63rd Street (city limits) was purchased to protect the source water and to extend the infiltration gallery.
In April of 1933, Water Works Park was opened to the public. At that time, the water supply grounds covered 1,400 acres. (Today, it spans 1,500 acres.)
Foreseeing a need for an emergency source of water, construction of a water storage reservoir near the Raccoon River southwest of Commerce began in 1943 (Maffitt Reservoir). Dale Maffitt, General Manager, was quoted in the Des Moines Tribune as saying it will insure an adequate water supply for Des Moines for many years to come.
Obviously, planning for the future didn’t end in the 1940s. Within the last 12 years, two additional water treatment facilities have been constructed. The L. D. McMullen Water Treatment Plant at Maffitt Reservoir began operation in 2000. Today, this water plant serves customers in southwest Des Moines, parts of Xenia and Warren Water Systems, Waukee and parts of Clive, Urbandale and West Des Moines. The Saylorville Water Treatment Plant went online in 2011 serving customers north of Des Moines. Long-range plans have been developed, future demand has been projected, and staff continues to prepare for the future, assuring there will be an adequate supply of water.
Des Moines Water Works (DMWW) has utilized two Aquifer Storage and Recovery (ASR) wells as sources of water for four years. These wells are installed deep into the Jordan Aquifer and used to store water that is needed when water demand is high – usually during the summer months when customers are using more water for irrigation of lawns and gardens. When water demand is low, mainly during winter months, DMWW will store drinking water down into the wells which displace the native Jordan water around the wells.
A total of 270 million gallons can be stored in each of two ASR wells during the winter months when DMWW has excess water treatment capacity. Then in the summer months, during higher water demand, the drinking water is pumped out of the ASR wells and into the water distribution system for use by customers. The water is pumped out of each of the ASR wells at three million gallons per day rate. These wells can pump for a total of 90 days to recover the 270 MG put into the wells.
The ASR wells can be constructed for about one-third the cost of adding capacity to an existing water treatment plant. These ASR wells are utilized to take capacity demand off the treatment plants.
This is just one of the methods DMWW uses to maximize the funds used to invest in the infrastructure required to deliver quality water to our customer in the quantities that they need.
Do you have projects requiring digging in your yard? Before you dig, be sure to include the most important step in your project plans: contact Iowa One Call.
Iowa One Call services are free and telephones are answered 24 hours a day. Utilities, including Des Moines Water Works, have 48 hours following a request to locate any underground facilities they have in the area and mark their location with flags or painted lines. After the excavation area has been marked, you will be able to avoid any underground services, preventing a loss of vital services and added expenses for repairs.
Iowa law applies to professional contractors as well as homeowners, and encompasses a wide array of outdoor projects including:
- Installing a fence
- Planting trees or shrubs
- Building a patio, addition, deck, garage, outdoor shed or any similar structure that requires any form of digging
- Putting in a new driveway
- Installing a septic system or water drainage system
- Terracing or landscaping
Call 811 or 1-800-292-8989 before you dig. It’s fast, it’s free, it’s the law! You can also access important information at www.iowaonecall.com.
Twenty years ago, Des Moines Water Works’ maintenance crews relied on paper maps, three-ring-binders, and thousands of index cards to track the location and maintenance history for every pipe, valve, and fire hydrant in the Des Moines water system. When information was needed regarding a specific item, crews would call the dispatch center, wait while the dispatcher looked in the files for the information, and then take notes as the dispatcher read information over the radio. The process worked, but it took time and there was the opportunity for errors in translation.
Today, all of Des Moines Water Works’ maintenance vehicles are equipped with an onboard computerized Geographic Information System (GIS). This system, which uses ESRI geo-database software, provides even more information than was available from the historic files, provides that information without the need to wait or communicate over the radio, and provides it in a graphical format which is much easier to read and understand.
Personnel in the field now have access to detailed information on every valve or fire hydrant in the system including location, date of installation, manufacturer, depth, most recent date of operation, operational concerns, etc. Information is also available related to water main failures, pipe fittings and alterations, and other features which are buried below ground. Right-of-way lines, property lines, and building footprints are also shown for all properties in the city.
The GIS system is also GPS-enabled which allows crews to find their current location within the mapping system with the click of a button. Having this information available at their fingertips helps Des Moines Water Works’ crews work more efficiently.
The 2012 capital improvements budget for Des Moines Water Works (DMWW) includes $6.4 million for water main and new feeder main projects. Of that amount, $2.8 million is budgeted for water system improvements within the Des Moines water distribution system. These funds will be used to replace water mains that have reached their useful life expectancy – water mains with a high occurrence of breaks. These funds are also used to replace small water mains (4-inch diameter and smaller) that do not provide adequate flows for fire protection. DMWW typically budgets between $1.5 and $3 million each year to replace these worn out and undersized water mains.
This is just one of the many efforts DMWW undertakes to ensure that infrastructure is replaced to ensure delivery of quality drinking water in the quantities that our customers need.
Water Day at the Iowa State Capitol is January 17, 2012, and Des Moines Water Works will be there on behalf of the approximately 500,000 people in DMWW’s service area.
Every Year, DMWW sees Water Day as an opportunity to talk with legislators from Central Iowa and across the state about improving and protecting water resources in the Raccoon and Des Moines Rivers, the sources of water for DMWW drinking water. Reducing nutrients, bacteria, and algae blooms in our source waters helps protect public health and contain the cost of treating drinking water for our customers.
This is also an opportunity to discuss protecting the utility’s $352 million of infrastructure from flood events – infrastructure owned by the citizens of Des Moines. In 1993, the Fleur Drive Treatment Plant was flooded and DMWW was not able to provide drinking water to customers for approximately 10-14 days. Since 2008, more than 65-feet of river bank have been lost at the L.D. McMullen Treatment Plant well field site, putting several wells at risk for damage. More frequent (and intense) rainfall events and expeditious movement of water off the landscape through tiling, have exacerbated flooding. The connectivity of surface water, ground water and soils exist on all levels and need to be managed as a system. The power of moving water, whether a raindrop or a torrent of flood water, can be better managed in Iowa.